Ceramic circuit board and manufacturing method therefor

A manufacturing method for a ceramic circuit board, comprising:

• forming a brazing filler layer on a first face of a ceramic substrate, the brazing filler layer including an active metal brazing filler;
• disposing a metal plate on the brazing filler layer;
• and
• bonding the ceramic substrate and the metal plate together by heating,
• the metal plate of the manufactured ceramic circuit board satisfying conditions in any cross section perpendicular to the first face, the conditions being such that
• a ratio Lb/Lt between a width Lb [mm] of a bottom side and a width Lt [mm] of a top side is not less than 1.005 and not more than 1.050,
• a ratio L1/L2 between a maximum width L1 [mm] and a minimum width L2 [mm] in an intermediate portion located between the bottom side and a distance 0.4 to 0.6 times a thickness T of the metal plate is not less than 1.0 and not more than 1.010,
• the ratio Lb/Lt is larger than the ratio L1/L2, and
• the width Lb is longer than the maximum width L1.